Tissue and plasma concentrations of cephuroxime during cardiac surgery in cardiopulmonary bypass — a microdialysis study

Aim: Wound and mediastinal infections are still very serious complications of open-heart surgery, in spite of the use of prophylactic antibiotics. The use of cardiopulmonary bypass (CPB) is associated with profound physiological changes affecting the pharmacokinetic behaviour of antibiotics.

The aim of this pilot study was to monitor the tissue concentrations of cephuroxime (prophylactic antibiotic) in skeletal muscle during cardiac surgery using CPB by interstitial microdialysis. These concentrations were compared with plasma concentrations of cephuroxime.

Material and methods: Nine adult patients operated on using CPB were enrolled in this study. Cephuroxime was used as a prophylactic antibiotic (1st dose — 3 g of cefuroxime i.v. with anesthesia induction, 2nd dose — 1.5 g i.v. after CPB with protamine sulphate, 3rd dose — 1.5 g i.v. 8 hours after the surgery).

Interstitial microdialysis was performed by probe CMA 60 (CMA Microdialysis AB, Sweden) inserted into the patient's deltoid muscle. Concentrations of cephuroxime in dialysates and in plasma were determined by the modified fluid chromatography method. The unbound cephuroxime fraction in plasma was obtained by using an ultrafiltration method. Samples of dialysates were collected at the following intervals: before CPB, each 30 minutes of CPB, at the end of CPB. Samples of blood were collected at these intervals: incision, start of CPB, each 30 minutes of CPB, at the end of CPB, at the end of surgery. Concentrations of cephuroxime in tissue were corrected by in vivo recoveries of the microdialysis probes.

Results: Plasma concentrations of cephuroxime were 163.5 ± 40.1, 79.3 ± 17.4, 73.7 ± 16.8, 66.1 ± 18.3, 57.0 ± 10.9, 120.7 ± 29.9 (mg . L—1) and concentrations of free plasma fraction of cephuroxime were 119.5 ± 35.2, 67.8 ± 15.5, 66.0 ± 12.5, 54.8 ± 12.2, 49.6 ± 9.8, 102.6 ± 26.0 (mg . L—1).

The concentrations of cephuroxime in dialysates were 44.3 ± 15.7, 36.1 ± 11.6, 31.9 ± 9.3, 34.6 ± 12.3, 27.6 ± 12.9, 56.7 ± 17.6 (mg . L—1).

The mean in vivo recovery of cephuroxime in this study was 30%.

Corrected concentrations (calculated by in vivo recovery) of cephuroxime in skeletal muscle were 148, 120, 106, 115, 92, 189 (mg . L—1).

Conclusion: Our preliminary results show that CPB can modify the time course of cephuroxime plasma and tissue concentrations. A decrease in plasma drug concentrations occurred at the start of CPB and lasted until CPB ended. An increase in plasma concentrations corresponds to the second drug dose after CPB. The concentrations of cephuroxime in skeletal muscle (corrected by recovery) during CPB are higher than plasma concentrations. It is influenced by important changes during CPB; closely associated with hemodilution, a shift of intravascular volume, solutes and albumin to the extravascular space and inconstant protein binding of cephuroxime during operation. Perfusion (2007) 22, 129—136.

Changes in metabolism and blood flow in peripheral tissue (skeletal muscle) during cardiac surgery with cardiopulmonary bypass: the biochemical microdialysis study

The aim of this study was to monitor the metabolism and blood flow in the interstitium of the skeletal muscle during cardiac surgery with cardiopulmonary bypass (CPB) and in the early postoperative period by means of microdialysis and to compare metabolic changes during CPB at normothermia (NT) and hypothermia (HT).

Surgical revascularization using CPB was performed in 50 patients, 25 patients (group HT) were operated using hypothermic CPB, 25 (group NT) using normothermic CPB. Interstitial microdialysis was performed by two CMA 60 probes (CMA Microdialysis AB, Solna, Sweden) inserted into the patient’s deltoid muscle. Constituents analysed in the obtained dialysates, collected at intervals, were glucose, urea, glycerol and lactate. Tissue blood flow was monitored by dynamic microdialysis with gentamicin as a marker.

In both groups, NT versus HT, similar dynamics of concentrations were found. Low initial concentrations were followed by gradual increases during CPB and in the following phase of the operation. Concentrations were higher in the NT group. Immediately after the operation, the decrease in values continued, with a gradual increase in the succeeding postoperative period in both groups. Similar dynamic changes in the lactate concentration were found in both groups. The gentamicin concentrations were lower in the NT group (versus the HT group).

The results showed dynamic changes in the interstitial concentrations of glucose, urea, glycerol and lactate, which depend on the phase of the surgery in the CPB and early postoperative phase in the both groups of patients. Higher tissue perfusion of the skeletal muscle was noted in those patients operated on in normothermia. The dynamics of the concentration changes of these substances in the interstitium of the skeletal muscle has been proven to be caused by both the metabolic activity of the tissue and by the blood flow through the interstitium of the muscle.

[Monitoring the effectiveness of surgical treatment of malignant pleural effusions]

BACKGROUNDS

Recurrent pleural effusion occured in 10% of cancer patients. Repeated thoracocentesis or drainage may be complicated by pneumothorax, haemothorax or pleural cavity infection. Thoracoscopic talc poudrage is one of the most effective pleurodesis technique in patients with malignant pleural effusions. The effectiveness of such pleurodesis is reaching the 70 to 90%. This surgical approach also allows to take a biopsy for histological verification of the process. An effort to predict the success rate of chemical pleurodesis on the basis of the body's general inflammatory reaction rate, which is determined by the dynamics of values of humoral and cellular inflammatory parameters in both serum and in pleural effusion.

PATIENTS

In the period 6/2008-12/2009 we applied biotalcum to 14 patients with malignant pleural effusions. The group of patients consisted of 10 male patients and 4 female patients of average age 71 years. Indication to include patients in the group was a second or further thoracic puncture, shortening of the interval between interventions, estimated time of survival > 3 months and the possibility of operation under selective pulmonary ventilation.

METHOD

We performed the collection of pleural effusion and blood serum at 12-hour intervals. The first collection was performed preoperatively before biotalcum application, and then during the time of losses from thoracic drainage bigger than 150 ml in 24 hours. The duration of thoracic drainage was 4 days +/- 1 day. The success of the treatment was observed by ultrasound scan before drainage removal; during the first three months always at intervals of 1 month and then after 3 and 6 months, depending on the progression of a disease.

RESULTS

No reccurence occured when the P-CRP (pleural) and S-CRP (serum) ratio exceeded 60% during the first 48 hours after pleurodesis. On the other hand, when the ratio fall bellow 30-35%, the effusion relapsed frequently.

CONCLUSION

The P-CRP/S-CRP ratio as a promising marker of talc pleurodesis effectiveness and monitoring both P-CRP and S-CRP levels is inexpensive and acceptable method for clinical practice. The pleural effusion caused by malignant mesothelioma appeares to be resistant to talc pleurodesis.

[Intra-aortic balloon counterpulsation in cardiac surgery patients--experiences of Department of Cardiac Surgery, Charles University, Faculty of Medicine in Hradec Králove, University Hospital Hradec Králové, Czech Republic]

AIM

To evaluate the use of intra-aortic balloon pump (IABP) at the Department of Cardiac Surgery, Charles University, Faculty of Medicine in Hradec Králové, University Hospital Hradec Králové and identifying the complications of this method and their frequency in long-term follow-up.

METHOD

Retrospective analysis of the outcome of IABP use. From September 1994 to September 2007, 10,024 cardiosurgery operations were performed at the Department of Cardiac Surgery, University Hospital Hradec Králové, Czech Republic. IABP was applied in 363 cases (3.6%). Therapeutic indication for initiation of IABP at our department was the syndrome of low cardiac output in the postoperative period and during operation (difficulty in weaning from cardio-pulmonary bypass) and severe acute ischemic changes of myocardium refractory to pharmacotherapy. Prophylactic IABP was elective introduction of support before cardiac surgery in hemodynamically stable high risk patients.

OUTCOME

From the group of 363 counterpulsated patients 192 were succesfully treated (52.9%), 171 patients (47.1%) died in consequence of cardiogenic shock and multiorgan failure. In 20 cases (5.5%) the IABP was introduced before the operation. Complications were observed in 61 patients (16.8%). Vascular complications were found in 27 cases (7.4%) including ischemic changes of the limb (14 cases 3.9%), significant bleeding occurred at the site of puncture (7 cases 1.9%), dissection of the femoral and iliac arteries (2 cases--0.55%), perforation of the iliac artery (1 case--0.3%). In 1 case (0.3%) the balloon was removed for intramural hematoma of the descending aorta without dissection. In 2 cases (0.55%) the balloon was led into the venous system. Thrombocytopenia occurred in our group in 23 patients (6.3%). Technical complications were observed in 7 cases (1.9%). None from our group of couterpulsated patinets had infectious complication.

CONCLUSION

IABP is an effective and clinically verified mechanical cardiac support. Our results are similar to other studies.

[Transcription factor KLF2 (Krüppel-like factor 2) and natural defence of vascular endothelium]

Vascular endothelium, monocytes and T-lymphocytes belong to the key cellular populations, which take an active part in the host's defence reactions. A successful course of these reactions is determined by a meticulous control of all phases since the very first steps until final healing of all incurred wounds. Any failure of the control mechanisms may lead to the development of chronic inflammatory diseases with an autoimmune component, such as the rheumatoid arthritis or atherosclerosis. An inflammatory reaction which is already under way is regulated by anti-inflammatory cytokines. However, of equal importance is the maintenance of cellular participants of inflammatory reactions in a quiescent state while no pro-inflammatory stimuli are present. One of the most important endogenous mediators, which prevent a self-initiated activation of endothelial cells, monocytes and T-lymphocytes, is represented by the transcription factor Krüppel-like factor 2. Its impact on the mentioned cells is almost identical with the so-called pleiotropic effects of inhibitors of the enzyme HMG CoA reductase or statins. This review article offers an insight into basic preventive mechanisms exerted by KLF2, notably those related to atherosclerosis.

[Cardiac surgery operations and their influence on serum level of antiinflammatory cytokine interleukin-10]

BACKGROUND

Cardiac surgical operation is followed by the development of inflammatory reaction. This reaction is regulated in many ways including the production of antiinflammatory cytokines such as IL-10 to avoid potentially harmful effects of inflammation.

METHODS AND RESULTS

We compared serum levels of cytokines IL-10, IL-6, and IL-13 in the group of patients undergoing cardiac surgical operation using either cardiopulmonary bypass (CPB, n=17) or surged on the beating heart (n=17). We found significant elevation in the serum level of IL-10 during surgery with the peak immediately after finishing surgery in CPB patients and at the first postoperative day in non-CPB patients, respectively. There is statistically significantly higher level of IL-10 in CPB patients in comparison with non-CPB patients at the end of surgery. Serum level of IL-6 is elevated in both groups during surgery reaching maximum immediately after surgery in CPB patients and at the first postoperative day in patients without CPB, respectively. The serum levels of IL-13 are only nonsignificantly changed during operation and in postoperative period in both groups.

CONCLUSIONS

The intensity of inflammatory response in CPB patients which is enhanced by massive contact activation of blood and extensive ischemia-reperfusion injury is regulated by the production of antiiflammatory IL- 10 cytokine.

[Interstitial microdialysis in the clinical and experimental medicine]

Interstitial microdialysis is a minimally invasive method that allows biochemical monitoring of endogenous and exogenous substances in extracellular tissue space. The method is based on sampling of soluble molecules from the interstitial space fluid by means of a semipermeable membrane. Microdialysis has been applied in primary and clinical research of metabolic changes and the blood flow in tissue interstitium and pharmacokinetic drug studies. Results obtained by microdialysis are gradually finding their place in clinical practice as well. This paper is aimed at presenting to the reader new technique of monitoring interstitial metabolism, its advantages, drawbacks and relevance for medicine.

[Shared pathogenesis of infectious and cardiovascular diseases--year 2005's view]

Entry of microorganisms into the blood stream provokes a decline in the contractile function of the cardiac muscle. Lipopolysaccharide of Gram-negative bacteria sets off production of pro-inflammatory cytokines including bactericidal concentrations of nitric oxide which set up the first defence line against bacteremia. At the same time, however, the performance of the cardiovascular system is negatively affected. The immediate menace resides in the occurrence of septic shock, while chronic infectious diseases that are accompanied by low-grade inflammation have been suspected to take an active part in the initiation and progression of atherosclerosis. This hypothesis, as attractive as it may appear, has not yet been accepted unequivocally. The article offers an up-to-date review of the signalling cascades which permit activation by lipopolysaccharide of the target cells. The same holds true for cellular activation by non-infectious stimuli. An emerging paradigm seems plausible that the same biologic events which serve to combat acute infection might be in the long run involved in the pathogenesis of atherosclerosis.

[Interstitial microdialysis study of changes in metabolism and blood flow in skeletal muscles during cardiac surgery with normothermic and hypothermic extracorporeal circulation]

AIM

Hypoperfusion of peripheral tissues and splanchnic organs during cardiac surgery in extracorporeal circulation may lead to the origin of serious complications. The aim of the study was to monitor metabolism and blood pressure in interstital peripheral tissue, skeletal muscle, during the operation on the patient with extracorporeal circulation (ECC) in an early post-operation period by means of microdialysis.

METHODS

The interstitial microdialysis is a minimally invasive method for the biochemical monitoring of metabolic changes and blood pressure in extracellular space of tissue. The substances in interstitium pass across a semipermeable membrane of the inserted microdialysis probe and may be analyzed. Microdialysis in this study was performed by means of two microdialysis probes CMA (CMA Microdialysis AB, Sweden) inserted into the deltoid muscle of the surgically treated patient. The probes were perfused by the Ringer solution at the rate of 0.3 ml/hour. The dialysates were sampled in the following intervals: beginning of the operation, beginning of ECC, end of ECC, end of the operation, two hours during the post-operation period. Standard biochemical methods were to evaluate, in the dialysates, glucose, urea, glycerol and lactate. The blood flow in the interstitium was monitored by means of dynamic microdialysis of gentamycine as a marker. Microdialysis was performed in 40 patients with ischemic heart disease, operated on in the extracorporeal circulation. In 20 patients the ECC was performed in normothermia (NT), while in the other 20 patients it was made in hypothermia (HT).

RESULTS

In both groups, NT versus HT, a similar dynamism of interstitial concentration of the observed substances in relation to the operation phase and in early post-operation period. Low initial concentrations were gradually increasing during the extracorporeal circulation and increased further after the end of extracorporeal circulation and also in the subsequent phase of the operation. The concentration values of the analytes under observation were higher in the groups operated on under normothermia, apparently due to normal cellular activity during normothermia (versus values in hypothermia). Immediately after the operation the observed values decreased in the both groups and subsequently gradually increased in the post-operation period in the both groups. The trend of dynamic changes of the observed analytes, selected as compounds indicating metabolic activity of skeletal muscles during hypothermia documents a lower metabolic activity of the cells during hypothermia and its marked increase (against NT) in the phase of subsequent normalization of the tissue temperature. Analysis of the concentrations of lactate, as a compounds mapping anaerobic metabolism of skeletal muscle, revealed similar dynamic changes in the both groups (NT vs. HT). There were no significant differences, related to the phase of the operation or the phase of immediate post-operation course when the both groups were compared. The analysis of gentamycine concentrations as a flow marker revealed lower gentamycine concentrations in dialysate during the operation, ECC and the early post-operation course in the group operated on in normotheramia (vs. HT), indicating a higher tissue flow in skeletal muscle against the group of patients operated on under hypothermia.

CONCLUSION

The results of the microdialysis study demonstrated dynamic changes in interstitial concentrations of the observed compounds (glucose, urea, glycerol and lactate) related to the phase of operation on the heart in extracorporeal circulation and in early post-operation period. A higher perfusion of skeletal muscle was documented in patients operated on under normothermia. It became obvious that the dynamism in the changes of the compounds observed in the interstitium of skeletal muscle was determined by metabolic activity of the tissue as well as by blood flow in the muscle interstitium.

[Control of blood loss with topical administration of aprotinin after pulmonary tissue decortication and pleurectomy]

The authors were prospectively monitoring postoperative blood loss in 23 patients, in which decortication of the lung tissue and pleurectomy was performed and in which 500,000 KIU of aprotinin was applicated locally to the operating field before closing chest. The study was performed between the years 1998 and 2001. The amount of blood loss was compared to that of a group of 23 patients who underwent the same type of surgery between 1991 and 1998 without use of aprotinin. The postoperative blood loss was monitored 6, 12 and 24 hours after completing the surgery. Postoperative blood loss was lower in the group of patients in which aprotinin was used which was found to be statistically significant compared to the group of nonaprotinin patients.

[Surgical myocardial revascularization in a female patient with bilateral occlusion of the common carotid arteries]

Concurrent stenosis of the coronary and carotid circulation is one of the most serious disease. The authors describe the case of a 74-year old female patient with ischaemic heart disease with concurrent bilateral occlusion of the common carotid arteries. Surgical revascularization of the myocardium was made using extracorporeal circulation under general normothermia with protection of the heart muscle from ischaemia by the method of warm blood cardioplegia. In the discussion the authors analyze contemporary possibilities of surgical treatment of ischaemic disease (MIDCAB, OPCAB, operations with extracorporeal circulation) and emphasize the advantages and risks of different procedures.

Morbidity and mortality in patients 70 years of age and over undergoing isolated coronary artery bypass surgery

BACKGROUND AND AIM

Due to the constantly improving results of surgical revascularization for coronary heart disease even the elderly patients are offered more frequently this type of treatment. Since older age is a harbinger of reduced vital capacity and increased morbidity the results of coronary artery bypass grafting (CABG) in elderly as well as long-term benefit deserve a careful examination.

MATERIALS AND METHODS

1475 isolated CABG procedures performed between 1995 and 1997 in a university hospital cardiac surgery unit, divided in group I (age below 70, n = 1324) and group II (age 70 and over, n = 151). A retrospective analysis of pre-operative, peri-operative and post-operative data.

RESULTS

Significant differences (lower BMI and BSA, advanced NYHA and CCS stage, higher prevalence of diabetes, renal dysfunction and extracardial atherosclerotic lesions) were found in elderly. CABG was performed in both groups with no differences in technique of procedure (only slightly longer duration of CPB in group II). However, there was markedly higher mortality (2.3 vs. 7.3%, p < 0.005), incidence of NearMiss+ (18.4 vs. 36.4%, p < 0.005) and post-operative morbidity (34.6 vs. 56.3%, p < 0.005) in the older group, which was also expressed in a longer ICU stay and postoperative hospitalization.

CONCLUSION

Coronary revascularization can be performed in elderly with higher but still acceptable risk. Higher mortality and associated morbidity is caused by higher preoperative prevalence of known risk factors as well as generally reduced vital capacity. Surgical procedure should not be denied to elderly population because of the age alone but a careful evaluation of an individual patient is required.

[Gastric perforation as an early complication of surgical myocardial revascularization using extracorporeal circulation]

The authors describe the case of a man with ischaemic heart disease after revascularization of the myocardium by an aortocoronary bypass using extracorporeal circulation. The early postoperative course was complicated by perforation of a gastric ulcer. The condition was successfully resolved by an urgent operation, suture of the perforated stomach with toilet of the abdominal cavity. In the discussion the authors analyze the causes of the possible development of gastrointestinal complications after cardiac surgery, in particular the influence of extracorporeal circulation and other specific effects during cardiac surgery and during the immediate postoperative period.

Sternobronchial fistula--uncommon complication after coronary surgery (a case report)

The authors describe a case of a 46-year-old man with ischemic heart disease who underwent coronary surgery. After some time span an inflamed wound, several skin fistulae and the system of substernal fistulae appeared. One of these fistulae communicated with the left bronchial tree.

Changes of the serum antibiotic levels during open heart surgery (ceftazidim, ciprofloxacin, clindamycin)

BACKGROUND

Wound, mediastinal and intracardiac infections are still very serious complications of open-heart surgery. The incidence of it is still in the range of 0.4%-5%. The aims of our study were to assess the adequacy of regimen using ceftazidim (CTZ), ciprofloxacin (CPF) and clindamycin (CLIN) as prophylactic antibiotics and to verify whether cardiopulmonary bypass (CPB) can modify the time of antibiotic serum concentrations. That is why the serum levels of them were measured during open heart procedures.

METHODS

The prospective study comprised 75 consequent coronary patients randomized in to three groups receiving 1 g of CTZ or 400 mg of CPF or 900 mg of CLIN i.v. with anesthesia induction. Routine coronary surgery with left internal mammary artery harvesting, moderate body hypothermic (30 degrees C) CPB with crystaloid cardioplegia was performed. Serum antibiotic levels were determined before application, with skin incision, prior CPB induction, after cardioplegia infusion, every 20 minutes of CPB, prior end of CPB, in time of chest closure. Conventional cylinder-plate microbiological assay was used for antibiotic level measurement.

RESULTS

All serum antibiotic concentrations showed a sharp decrease immediately after starting CPB and lasted until CPB ended. After initiating of CPB after cardioplegia administration serum concentrations of CTZ (105 min after initial dose) decreased by, on average 55%, CPF (97 min) by 42% and CLIN (116 min) by 78%.

CONCLUSION

CPB can modify the time course of antibiotic serum concentrations. The serum levels of CTZ at the end of the longest procedures were found to be below the MICs for some of the suspected pathogens. We recommend to use higher antibiotic doses for prophylaxis and to administer the second dose with protamin sulphate to obtain maximum concentration in newly formed blood clots.

Topical use of aprotinin in coronary artery bypass surgery

OBJECTIVE

The internal mammary artery (IMA) ranks among excellent, widely used conduits for surgical coronary revascularization. Its harvesting and its using may cause other surgical and technical problems and complications and increase postoperative bleeding from wound surface after the IMA harvesting with significantly greater incidence of blood transfusion. The aim of this study was to get to know how much it increases postoperative bleeding losses and if the local application of aprotinin (to the wound surface after the IMA harvesting and into the pericardial cavity) can reduce them and thus decrease the number of blood transfusions.

METHODS

In this study there are compared groups of patients (n = 275) operated at the University Department of Cardiac Surgery in Hradec Králové on account of ischemic heart disease. In the first part of this study results of operations of 200 patients were comprised retrospectively. Group A1 comprised 50 patients where for revascularization of the myocardium venous grafts were used. Group B1 comprised 50 patients where also the internal mammary artery was used. Group C1 was formed by 50 patients where after preparation of the IMA aprotinin (100,000 KIU) was administered locally to the wound surface after the IMA harvesting. Group D1 was formed by 50 patients where aprotinin (500,000 KIU) was administered locally to the wound surface and poured into the pericardial cavity before closure of the median sternotomy. The postoperative blood losses and the number of the administered blood transfusions were compared between these groups.

RESULTS

The authors provided evidence that the using of the IMA increases significantly the postoperative blood losses (in group A1 675 ml +/- 352.9, in group B1 1232 ml +/- 336.5) and increases the number of required transfusions (in group A1 2.44 +/- 1.7, in group B1 3.45 +/- 1.0). By local aprotinin application to the wound surface after the IMA harvesting the blood losses and the number of administered transfusions were reduced in group C1 (896 ml (231.9, 2.74 +/- 0.8). In group D1 (local aprotinin application to the wound surface and into the pericardial cavity) the blood losses and the number of transfusions were increasingly reduced than in group C1 (797 ml +/- 280.5, 1.74 +/- 1.3). In the second, prospective randomised part of this study 3 groups of patients were compared. Group A2 comprised 25 patients where venous grafts for revascularization of myocardium were used. Group B2 was formed by 25 patients where also the IMA was used. Group D2 comprised 25 patients where aprotinin (500,000 u.) was administered locally to the wound surface after the IMA harvesting and poured into the pericardial cavity before closure of sternotomy. The postoperative blood losses and the number of administered blood transfusions were again compared between these groups. The total postoperative blood losses were 778 ml +/- 304.2 in group A2, 1072 ml +/- 391.8 in group B2 and 754 ml +/- 197.9 in group D2. There were compared blood losses after 6, 12 and 24 hours, too. There were the statistically significant differences among these groups during the whole postoperative period. The number of blood transfusions were 2.8 +/- 2.3 in group A2 and 2.04 +/- 1.1 in group B2. The use of aprotinin decreased this number in group D2, 1.44 +/- 1.1.

CONCLUSIONS

The authors provided evidence that the harvesting and the using of the internal mammary artery for myocardial revascularization increases significantly the postoperative bleeding and increases the number of required transfusions. By local application of aprotinin the author reduced the blood losses and need of transfusions.

[Surgical myocardial revascularization in ischemic heart disease in a patient with a transplanted kidney]

The authors presents their first experience with coronary artery surgery in a patient after previous renal transplantation. They describe differences in the preoperative preparation, cardiac operation and postoperative care, with possible risk and complications.

[Kinetics of ceftazidime in prophylactic administration during cardiopulmonary bypass]

Serum ceftazidime levels were followed in 21 patients in which routine coronary bypass surgery with cardiopulmonary bypass was performed. Each patient received one gram of ceftazidime intravenously with anesthesia induction. Antibiotic concentrations were estimated using the microbiologic assay diffusion plate method. The average operation time was 220 +/- 41 minutes (range 130-310). The start of cardiopulmonary bypass was 86 +/- 21 minutes and the full flow time was 104 +/- 21 minutes after starting of ceftazidime application. It can be stated that the decline of ceftazidime serum levels after starting of cardiopulmonary bypass was faster in comparison with standard serum curves of this antibiotic. The concentrations of ceftazidime at the end of some operations were under the supposed minimal inhibitory concentrations for some microorganisms possibly implicated. No infection was recorded.

Concomitant coronary and asymptomatic carotid artery disease in patients prior to myocardial revascularization

The authors report on the results of ultrasound examinations of the carotid arteries in 525 patients with ischemic heart disease, hospitalized at the Department of Cardiac Surgery in Hradec Králové, prior to myocardial revascularization. Only 213 patients (40.6%) had intact carotid bed. The remaining 312 patients (59.4%) were found to have asymptomatic sclerotic changes of varying degrees of severity. Haemodynamically significant stenoses of over 50% were found in 64 cases (12.2%). 19 patients (3.6%) had critical stenoses of over 85% or occlusions of one or both internal carotid arteries. Comparison between patients younger than 65 and older than 65 showed significant increase of sclerotic changes in the older group. The authors prefer to perform myocardial revascularization procedure in hypothermic CPB with alpha-stat regime before carotid artery surgery. Combined procedures are preferred only in cases with concomitant neurologic and coronary symptomatology or in cases with severe carotid stenoses or occlusions of both arteries.

[Bacteriological findings in bronchial secretions of the lower respiratory tract in resected lungs]

The authors investigated during operation the bacteriological findings in the bronchial secretion of the respiratory pathways of resected lungs. Of 100 patients whom they included in the group they detected a positive finding in 42. Wound in 27 patients. Twenty of them had a positive bacteriological finding in the lower respiratory pathways. The authors discuss the problem of prophylactic use of antibiotics in pulmonary surgery. Based on data in the literature and their own observations, the authors recommend preventive administration of antibiotics in pulmonary surgery.

[Mediastinal inflammation as a complication of heart surgery under extracorporeal circulation]

The authors describe mediastinitis in two patients operated on account of ischaemic heart disease. In both patients they used the closed approach which involved suture of the sternum and surgical wound, perfect drainage and the administration of antibiotics (general and local). They describe the applied method of fixation of the sternum. In both patients the sternum and surgical wound healed.